Triumph TR6

Triumph TR6 owners are more knowledgeable than most when it comes to fuel injection - certainly the mechanical injection of the Triumph 'PI' cars could produce good power. Unfortunately, this was a long time ago when fuel cheap! It's not the most flattering photo, but what really makes this car stand out from the crowd is under the bonnet...

The owner of this car is enthusiastic about the benefits of LPG, and combined with an electronically controlled fuel injection system he's able to flip between petrol and gas at the push of a button.

Engine speed and timing information is taken from a 36-1 trigger pattern machined into the crankshaft pulley. The LPG ECU intercepts signals to and from the Canems unit to calculate the quantity of gas required.

Having previously run with mechanical injection, converting to EFI was relatively straightforward. The original mechanical injector positions were used for the electronic injectors, and a new fuel pressure regulator reduces fuel pressure from approximately 105 PSI down to 45 PSI. The owner of this car was fed up with balancing the individual throttles, so they were removed in favour of a larger single throttle butterfly placed at the end of the plenum.

As it stands, the mapping for LPG still needs some fine-tuning, but the basics are all there. When the LPG system takes over, the Canems unit is still providing ignition by means of a wasted spark coil pack. Once the car is running on gas, the ignition can be advanced to take full advantage of the high octane rating - an advantage that comes about through the switchable maps in the Canems ECU.

This is an exciting project that can only enhance the appeal of a classic sports car like this - not only will performance and reliability be improved, but fuel economy and emissions too, by quite a considerable margin.